The O-Ring seal surface abrasion is a one of the most frequent cases of breakage in the dynamic seal applications.The repetitive rubbing between the ring and the housing surfaces lead to the heating of the O-Ring surfaces, which consequently increases the friction and the modification of the compound characteristics. These factors provoke wear and tear and formation of lacerations on the ring surfaces (figure 9.3). The presence of a thin layer of lubricant can slow down the O-Ring deterioration . The damage provoked by the abrasion is present only on one side making the identification of the cause of the damage easier.
O-Ring with grazed surfaces and consequent breakage
Figure 9.3
O-Ring with grazed surfaces and consequent breakage
Even being a case linked mainly to the relative movement between the elements, it is possible to have a loss of efficiency of the necessary seal to the abrasion also in static applications, when the exercise pressure is pulsing and with strong variations of peaks. In this case the abrasion is provoked by the small shifting which the O-Rings are subjected to. A good surface finishing, combined with the ring lubrication and the usage of the fluids without solid impurities, can reduce in a considerable way the possibility of breakages due to O-Ring abrasion.
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